Cardiovascular Critical Care II
Patient Case
in the cafeteria, and while in line to check out, she collapses. The emergency response team of which you
are part is summoned. L.S. does not respond to voice or tapping of the shoulder, and a brief look at her
chest shows no chest movement. Chest compressions are initiated while the crash cart and defibrillator are
retrieved. Of note, a bag-mask ventilator is available at the scene because it is carried with the emergency
response team. Which is most accurate about L.S.’s airway and breathing management?
mended only in single-rescuer resuscitations.
given as synchronous ventilations.
oxygen and eliminate CO2.
Rapid defibrillation with a manual or automated external defibrillator (AED) (IHCA and OHCA - chain
of survival)
Defibrillation shock = unsynchronized shock.
Successful defibrillation is defined as 5 seconds or greater of termination of arrhythmia after a
shock is delivered.
Early defibrillation of VF is crucial because it is the most common rhythm in witnessed OHCA,
survival diminishes rapidly over time, and VF often progresses to asystole (Resuscitation 2000;44:7-
17; Circulation 1997;96:3308-13).
| d. | Three key actions must occur within moments of VF SCA to increase the likelihood of survival: (1) |
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activation of the emergency medical services system (e.g., emergency response team), (2) provision
Performing chest compressions while a defibrillator is obtained significantly improves the probability
of survival (Circulation 2009;120:1241-7). When VF is present for more than a few minutes, the
myocardium becomes depleted of oxygen and energy substrates (e.g., adenosine triphosphate [ATP])
(Grover 1977).
CPR can provide the oxygen and ATP needed until the shock is delivered.
ii.
Increased likelihood of termination of VF from shock delivery and ROSC if CPR given first
iii.
If CPR is initiated immediately, survival can double or triple at most time intervals until
Med 1993;22:1652-8).
Early defibrillation is a powerful predicator of ROSC after VF.
Survival rates are highest for VF when CPR and defibrillation occur within 3–5 minutes of the
event (Circ Cardiovasc Qual Outcomes 2010;3:63-81; Resuscitation 2009;80:1253-8). In the
IHCA setting, prompt defibrillation (less than 2 minutes from the VF event) was associated
with higher rates of long-term survival (Circulation 2018;137:2041-51).
| (a) | For every minute that passes after collapse, survival from VF decreases 7%–10% (Ann |
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Emerg Med 1993;22:1652-8).
| (b) | CPR prolongs VF and delays the progression to asystole (Resuscitation 2000;47:59-70; |
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